Streaming video in HD and full-screen is choppy with low fps. Will a new GPU solve my issue?

[Billspear]

So video's streaming full-screen in 480p aren't perfect but they are watchable. However, when I switch to 720p or 1080p, forget it. Not worth it. My CPU stays around 65-75% not in full-screen.

I must say that I'm working with old hardware:

Core 2 Duo E6700 2.66GHz (Dual-Core LGA 775)
3GB DDR2 667MHz
NVIDIA 8500GT

I was planning on taking out the 8500GT and throwing in a Radeon HD 4670 which is supposedly 300% better than my current one and it has 4x the amount of VRAM. Will this certainly help my issue?

 

[Zmanrocks]

Yes a new GPU will fix your "choppy low fps issue" and yes the Radeon HD 4690 will help ALOT